Capacitors have many industrial uses. For example, motors used for compressors, pumps, and refrigeration and air conditioning equipment typically utilize a capacitor to improve the starting and/or operating performance of the motor. In many cases, however, the capacitor is not an integral component of the motor and must be mounted to the motor's housing prior to operation. Typically, this is accomplished by using a special bracket or by placing the capacitor within a shell and fastening the entire assembly to the motor housing.
A conventional capacitor assembly is shown in FIG. 1. This assembly includes a capacitor, an insulating board, and a metal shell commonly referred to as a "doghouse." The capacitor is completely sealed within a phenolic case and has terminals which extend from an open end in the case. Prior to operation, a user must electrically connect the motor to the capacitor's terminals and insert the phenolic case into the "doghouse." The insulating board is placed between the capacitor's terminals and the "doghouse" to prevent electrical shorts during operation. Once the individual components have been assembled, the "doghouse" must be securably fastened to the motor housing.
Conventional capacitor assemblies such as those exemplified in FIG. 1 have several shortcomings. For example, as discussed above, the capacitor assembly shown in FIG. 1 requires considerable assembly prior to operation. The user must first connect the terminal leads from the capacitor to the motor. In many situations, this typically involves the user soldering the motor leads to the capacitor terminals. Moreover, assembly is made more difficult due to the fact that the capacitor's terminals extend outward from the capacitor body instead of in a direction facing the motor housing.
Moreover, the capacitor assembly shown in FIG. 1 requires a snug fit between the phenolic case and the "doghouse." Thus, in a situation where the phenolic case is too large, it may not fit into the "doghouse," further increasing the difficulty of assembly. Similarly, in a situation where the phenolic case is too small, the resulting capacitor assembly is unstable and susceptible to motor vibrations.
Furthermore, conventional capacitor assemblies are often very large and heavy with respect to their intended use. Despite the electrical requirements for the capacitor, the size and weight of the assembly is largely dependent upon the phenolic shell and metal "doghouse." As described above, the capacitor body is first inserted and sealed within the phenolic case which in turn must fit within the metal "doghouse." The resulting capacitor assembly is often unnecessarily large and heavy. Typically, capacitor assemblies made according to the prior art have a diameter substantially equal to the diameter of the motor housing. Moreover, in order to customize an existing assembly, a user must specify changes in the size of the phenolic case as well as the metal "doghouse."
Accordingly, there arises a need to provide a monolithic capacitor assembly having substantially the same performance characteristics as conventional capacitor assemblies yet, with the added feature of being easy to assemble/mount prior to operation. Furthermore, there is a need to provide a capacitor assembly that is sized appropriately for the needed application. Such a capacitor assembly would provide a more efficient and secure method of assembly and substantially reduce costs associated with installation. The present invention directly addresses and overcomes the shortcomings of the prior art.